In a large bowl, using an electric/stand mixer (or hand whisk, just double/triple the times) combine the butter and both sugars on medium speed for several minutes, until fully combined. Add the egg and vanilla and mix again.
Add the flour and baking powder, plus a pinch of salt, and fold in using a rubber spatula or wooden spoon, until just combined. The dough should be fairly solid at this stage (it ought to almost form a ball, albeit a very soft one!). Add the chocolate, cranberries, orange zest and juice and stir together.
Let this dough chill in the fridge for at least 30 minutes.
Preheat oven to 200C/180C Fan/Gas Mark 6. Line 2-3 large baking trays.
Scoop large balls of cookie dough – about 1 tbsp in size, so you have 12 of similar size. Place on the trays, with several inches in between (max 3 per tray).
Bake for 10-12 minutes, until just golden at the edges. They may look a little underbaked in the centre but they keep cooking from the residual heat, and this gives them their perfect soft texture. Repeat for all cookies and leave to cool on a wire rack before serving.
